• Only 3% of the world's water is drinkable. The rest is either contaminated, or seawater, or both.

• In terms of volume, 75% of your bonce is made up of water. Water also figures large in terms of body tissue. It plays a vital role in supplying oxygen to cells, as well as temperature regulation, waste removal and the everyday running of all major organs. Without it, you're biscuit.

• You can go about four weeks without food, but only three days without water.

• For maximum health, experts reckon you should drink approximately two litres of water (eight glasses) each day. Coffee and booze don't count, because both have a diuretic effect on the body. Caffeine and alcohol both serve to squeeze water from cells, which means you lose more fluid than you take on board.

• If you wait until you're thirsty before you reach for that glass, then you're already dehydrated and the damage is done.

• When the body is dehydrated, it often sends out signals that are misread as hunger pangs. Mild dehydration actually slows down body metabolism, so you're losing out on two counts if you let your water intake slip.

• A little dehydration can leave you feeling tired as well as messing with your short-term memory. Start to feel a bit parched, and simple mental tasks could seem like a massive Jedi mind challenge.

• It's advisable for pregnant women to increase their daily water intake to meet the needs of the developing foetus. Mothers who breastfeed should also keep spinning the cold tap to replace fluid used in milk production.

Updated: 26/08/2010